GSpot

GSpot is a free "codec information appliance", i.e. an application that tells you about the codec(s) used in a video file. It's very simple yet surprisingly useful. Basically you just open any video or audio file, GSpot analyses it and tells you which codecs were used. What makes it so great for many people is that it tells you what to do if you don't have the correct codecs installed. Got an AVI file that won't play, or an MPEG file that seems to have lost the audio? Run it through GSpot and see what's wrong.

There is no installation as such. Simply download the file, then double-click the executable file to run it. If only all applications were like this.

As well as information about codecs, GSpot will show you metadata, resolution, frame rate and more.

Note that the information isn't always exactly what you need to solve every problem. For example, the screenshot above shows an MPEG file that can be played on the computer, but what it doesn't reveal is that the file cannot be imported into many editing applications due to incompatibilities with the audio codec.

On the whole this is an excellent application, well worth having on hand to help diagnose video and audio problems. And it's free!